Jessica Lange plays a witch named Fiona Good in 'American Horror Story: Coven.' She's written a book for kids. / FX

by Jocelyn McClurg, USA TODAY

by Jocelyn McClurg, USA TODAY

On the new season of American Horror Story: Coven (premieres Oct. 9 at 10 p.m. ET/PT on FX), Jessica Lange trades in her nun's habit for black Prada and Balenciaga as a glammed-up witch.

Sadistic Sister Jude and her caning may be gone, but Fiona Goode, Lange's new character, comes with her own warning: "The only thing you have to be afraid of is me," she threatens in the trailer, before sending teenage girls flying with a flick of her wrist.

AHS starts afresh each season, with new characters, a new story line and a new setting.

Airborne adolescents aside, Lange believes that the tone of Season 3 is lighter than last year's Asylum, which took place in the 1960s at the horrifying Briarcliff Mental Institution.

"What happened last year is we headed down this dark rabbit hole that got darker and darker and darker and darker. I think there has been an effort this year to not go quite that dark. It's still about horror, but maybe more psychological this year."

The actress, 64, stars as a "Supreme" witch descended from Salem who's used to hobnobbing with celebrities. ("She has lived the high life," Lange says.) Fiona returns home to Miss Robichaux's Academy for young witches in New Orleans hoping to rule her Coven again, and perhaps patch up things with her estranged daughter (Sarah Paulson), the school's headmistress.

While declining to offer up many plot points ("It's a closely guarded secret," she says of the series created by Ryan Murphy), Lange reveals that one of her favorite moments so far happens in Episode 1.

"There's a scene which was a wild, wild, toes-wild ride, flat-out crazy fun to do, yet it has a real darkness to it."

The Oscar-winning actress, who won an Emmy for her role as Constance Langdon in AHS's first season and was nominated for Sister Jude, likes being able to play an outrageous new character each season. "They've been great parts, and they've allowed me to really do things I've never done before. It's been a real treat for me."

She is committed to one more season of AHS after this one, "then I don't know what will happen."

Right now, she and the show's creators are talking about her character for Season 4. "It's really exciting," she teases, before adhering to the AHS code of silence.